With the ktor 2.0 `testApplication` block, I’m trying to test some lifecycle hooks for a custom plug...

# ktor

[phldavies]

With the ktor 2.0 testApplication block, I’m trying to test some lifecycle hooks for a custom plugin. Is there a nice way to ensure the application environment is started than making a client call? I currently have something like this:

private suspend fun ApplicationTestBuilder.ensureStarted() = client.get("/") { expectSuccess = false }

class MyTest : FunSpec({
    test("plugin works correctly") {
        testApplication {
            install(MyCustomPlugin) { ... }

            ensureStarted()

            // test the plugin
        }
    }
})

[Aleksei Tirman [JB]]

Could you please describe why do you need to test it? The application environment should be started in a test.

[phldavies]

The plugin starts a Job on ApplicationStarted event, which won’t fire until the application environment is started. With the testApplication construct, there’s no way to explicitly start the application beyond as a side effect of the first call through the provided (or a constructed) client . I need to test that the Job starts and operates correctly.

[Aleksei Tirman [JB]]

What is the use for this job?

[phldavies]

It sets up kafka consumers, currently. However this problem would apply to any plugin that would like to handle the application lifecycle events from Ktor.

[Aleksei Tirman [JB]]

Do you mean that you can’t test your essential plugin logic without first making a request to start an application environment?

[phldavies]

Yes, exactly that. The only way to start the test application environment is to make a request. I could potentially use the TestApplication builder and manually start and stop the application, however this doesn’t allow to accessing the client within the builder, unlike testApplication - which is needed to access any externalServices defined in the test application.

[Aleksei Tirman [JB]]

Could you please file an issue about this problem?